#include <ctype.h>
#include <errno.h>
+#include <grp.h>
#include <pwd.h>
#include <stdarg.h>
#include <stdlib.h>
#include "config.h"
-typedef struct {
+struct lock {
int screen;
Window root, win;
Pixmap pmap;
unsigned long colors[NUMCOLS];
-} Lock;
+};
-static Lock **locks;
-static int nscreens;
-static Bool rr;
-static int rrevbase;
-static int rrerrbase;
+struct xrandr {
+ int active;
+ int evbase;
+ int errbase;
+};
static void
die(const char *errstr, ...)
}
#endif
-/* only run as root */
static const char *
getpw(void)
{
}
#endif /* HAVE_SHADOW_H */
- /* drop privileges */
- if (geteuid() == 0 &&
- ((getegid() != pw->pw_gid && setgid(pw->pw_gid) < 0) || setuid(pw->pw_uid) < 0))
- die("slock: cannot drop privileges\n");
return rval;
}
static void
-readpw(Display *dpy, const char *pws)
+readpw(Display *dpy, struct xrandr *rr, struct lock **locks, int nscreens,
+ const char *pws)
{
char buf[32], passwd[256], *encrypted;
int num, screen, running, failure;
}
oldc = color;
}
- } else if (rr && ev.type == rrevbase + RRScreenChangeNotify) {
+ } else if (rr->active && ev.type == rr->evbase + RRScreenChangeNotify) {
XRRScreenChangeNotifyEvent *rre = (XRRScreenChangeNotifyEvent*)&ev;
for (screen = 0; screen < nscreens; screen++) {
if (locks[screen]->win == rre->window) {
}
}
-static void
-unlockscreen(Display *dpy, Lock *lock)
-{
- if(dpy == NULL || lock == NULL)
- return;
-
- XUngrabPointer(dpy, CurrentTime);
- XUngrabKeyboard(dpy, CurrentTime);
- XFreeColors(dpy, DefaultColormap(dpy, lock->screen), lock->colors, NUMCOLS, 0);
- XFreePixmap(dpy, lock->pmap);
- XDestroyWindow(dpy, lock->win);
-
- free(lock);
-}
-
-static void
-cleanup(Display *dpy)
-{
- int s;
-
- for (s = 0; s < nscreens; ++s)
- unlockscreen(dpy, locks[s]);
-
- free(locks);
- XCloseDisplay(dpy);
-}
-
-static Lock *
-lockscreen(Display *dpy, int screen)
+static struct lock *
+lockscreen(Display *dpy, struct xrandr *rr, int screen)
{
char curs[] = {0, 0, 0, 0, 0, 0, 0, 0};
int i, ptgrab, kbgrab;
- Lock *lock;
+ struct lock *lock;
XColor color, dummy;
XSetWindowAttributes wa;
Cursor invisible;
- if (dpy == NULL || screen < 0 || !(lock = malloc(sizeof(Lock))))
+ if (dpy == NULL || screen < 0 || !(lock = malloc(sizeof(struct lock))))
return NULL;
lock->screen = screen;
/* input is grabbed: we can lock the screen */
if (ptgrab == GrabSuccess && kbgrab == GrabSuccess) {
XMapRaised(dpy, lock->win);
- if (rr)
+ if (rr->active)
XRRSelectInput(dpy, lock->win, RRScreenChangeNotifyMask);
XSelectInput(dpy, lock->root, SubstructureNotifyMask);
int
main(int argc, char **argv) {
+ struct xrandr rr;
+ struct lock **locks;
+ struct passwd *pwd;
+ struct group *grp;
+ uid_t duid;
+ gid_t dgid;
const char *pws;
Display *dpy;
- int s, nlocks;
+ int s, nlocks, nscreens;
ARGBEGIN {
case 'v':
usage();
} ARGEND
+ /* validate drop-user and -group */
+ errno = 0;
+ if (!(pwd = getpwnam(user)))
+ die("slock: getpwnam %s: %s\n", user, errno ?
+ strerror(errno) : "user entry not found");
+ duid = pwd->pw_uid;
+ errno = 0;
+ if (!(grp = getgrnam(group)))
+ die("slock: getgrnam %s: %s\n", group, errno ?
+ strerror(errno) : "group entry not found");
+ dgid = grp->gr_gid;
+
#ifdef __linux__
dontkillme();
#endif
if (!(dpy = XOpenDisplay(NULL)))
die("slock: cannot open display\n");
+ /* drop privileges */
+ if (setgroups(0, NULL) < 0)
+ die("slock: setgroups: %s\n", strerror(errno));
+ if (setgid(dgid) < 0)
+ die("slock: setgid: %s\n", strerror(errno));
+ if (setuid(duid) < 0)
+ die("slock: setuid: %s\n", strerror(errno));
+
/* check for Xrandr support */
- rr = XRRQueryExtension(dpy, &rrevbase, &rrerrbase);
+ rr.active = XRRQueryExtension(dpy, &rr.evbase, &rr.errbase);
/* get number of screens in display "dpy" and blank them */
nscreens = ScreenCount(dpy);
- if (!(locks = calloc(nscreens, sizeof(Lock *)))) {
- XCloseDisplay(dpy);
+ if (!(locks = calloc(nscreens, sizeof(struct lock *))))
die("slock: out of memory\n");
- }
for (nlocks = 0, s = 0; s < nscreens; s++) {
- if ((locks[s] = lockscreen(dpy, s)) != NULL)
+ if ((locks[s] = lockscreen(dpy, &rr, s)) != NULL)
nlocks++;
else
break;
XSync(dpy, 0);
/* did we manage to lock everything? */
- if (nlocks != nscreens) {
- cleanup(dpy);
+ if (nlocks != nscreens)
return 1;
- }
/* run post-lock command */
if (argc > 0) {
switch (fork()) {
case -1:
- cleanup(dpy);
die("slock: fork failed: %s\n", strerror(errno));
case 0:
if (close(ConnectionNumber(dpy)) < 0)
}
/* everything is now blank. Wait for the correct password */
- readpw(dpy, pws);
-
- /* password ok, unlock everything and quit */
- cleanup(dpy);
+ readpw(dpy, &rr, locks, nscreens, pws);
return 0;
}